The present invention relates to transformers. One type of transformers to which the invention relates is shown in FIG. 1 of the accompanying drawings, wherein reference number 10 designates an "E"-shaped core element. The central part of the core element 10 passes through the central opening of a coil 11 resting on an insulating channel 12 which, in turn, rests on the E-shaped core element. Reference numeral 14 denotes an I-shaped member. The I-shaped member 14 is welded to the core element 10. Both the I-shaped member 14 and the core element 10 are made of iron laminations as is well known in the art. A typical arrangement of terminals of a transformer of prior art provides a plurality of metallic terminals 15, 16, 17, 18, etc. which are generally L-shaped and include each a horizontal plate portion with a clamping screw and a normally generally vertically directed portion to which is secured the end of a respective winding of the transformer coil. The securement of the windings to the terminals 15-18 and the mounting of the terminals to the coil itself is cumbersome and time consuming and thus expensive. Moreover, the terminals are inadequately supported physically and are exposed to mechanical damage and breakage. Also, they are prone to electrical shorting.
U.S. Pat. No. 3,516,040 issued June 2, 1970 to J. F. Ripley et al. presents an improvement wherein the horizontal plate sections of the terminals such as terminals 15-18 are embedded in a molded plastic support which is also provided with a number of partitions separating each terminal plate from the other. The metallic terminals of this arrangement are no longer exposed to mechanical damage. They are sufficiently insulated from each other and from the core of the transformer. However, the time consuming and thus expensive attaching of the metallic terminals to the transformer is still present. Also, the molding of the entire casing is expensive.
The object of the invention is to further advance the art of transformers by improving structural features of the terminal blocks and the terminals thereof which would retain the advantages of the arrangement as shown in Ripley et al. and would also very substantially facilitate the assembly of the transformer and in particular the securement of the metallic terminals to the transformer.
It is another object of the invention to provide such an arrangement of the terminal block, the coil and the core, which would provide the required creepage distance between the coil and the core at the corners thereof, without unduly increasing the manufacturing costs.